西藏当雄拉屋矿区污染土壤微生物及其活性研究

Research on microorganism and microbial activity of contaminated soil at Dangxiong Lawu mine area in Tibet

通过现场采样及室内培养分析,研究了西藏当雄拉屋矿区污染土壤微生物区系组成、主要生理类群及其活性。结果表明:矿区土壤受重金属Cu、Zn、Pb、Cd不同程度污染,矿区污染土壤几种重金属质量分数比非矿区土壤有明显的增加。矿区土壤微生物区系组成和各生理类群发生了明显变化,土壤细菌、真菌、放线菌以及各生理类群数量均显著降低,且3大微生物以及各生理类群对矿区污染的敏感性大小分别表现为放线菌>细菌>真菌,硝化细菌>氨化细菌>纤维分解菌。矿区土壤酶活性较低,对照土壤的各种酶活性最高,而矿区土壤基础呼吸和代谢商则受到刺激明显提高,其中土壤脱氢酶的活性变化最大,作为矿区重金属污染的指标更灵敏。可见,土壤中微生物区系组成及参与物质转化的生理类群种类、数量及土壤酶活和微生物活性在一定程度上可反映该矿区污染生境的重金属污染特征及其生态功能的演变规律。

Microflora composition,major physiological groups and microbia activity of polluted soil were analyzed at Dangxiong Lawu mine area in Tibet by sampling and under the conditions of indoor culture.The results showed that the mine soil was polluted by heavy metals of Cu,Zn,Pb,Cd at different degree,and the contents of heavy metals in contaminated mine soil increased greatly than non-mine areas.The microflora composition and the microorganism groups changed significantly at polluted mine soil.The quantity and physiological groups of soil bacteria,fungi and actinomycetes decreased obviously in polluted mine soil,and the susceptive order of three soil micro-organims and physiological groups to the polluted mine soil was actinomycetes bacteriafungi,and azotobacteria nitrobacteria ammonifing bacteria cellulose decomposition bacteria.Enzyme activity at mine soil was lower than that at non-mine soil.The basal respiration and metabolic quotient at mine soil were significantly increased by stimulation,in which the greatest changes in soil was dehydrogenase activity what was more sensitive indicators of heavy metal pollution.Therefore,the microflora composition,physiological groups,quantity,activity of soil enzyme and microorganism on transformation substance in soil could reflected the characteristics of heavy metal pollution characteristics,and the evolvement law of ecosystem function in polluted mine area at Dangxiong Lawu mine.